Heat dissipation device with a heat pipe

ABSTRACT

A heat dissipation device includes a base for contacting with a heat-generating electronic component, a fin assembly, a heat pipe connecting with the base and the fin assembly, and a holder connecting with the base and the fin assembly and supporting the heat pipe. The fin assembly includes a plurality of fins far away from the base. The heat pipe includes an evaporation portion thermally engaging with the base, a condensation portion connecting with the fin assembly and a connecting portion connecting with the evaporation portion and the condensation portion. The holder has a profile similar to the connecting portion of the heat pipe.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to heat dissipation devices, andmore particularly to a heat dissipation device having a heat pipe forcooling an electronic component, such as an integrated circuit package.

2. Description of related art

Electronic components, such as central processing units (CPUs), comprisenumerous circuits operating at high speed and generating substantialheat. Under most circumstances, it is necessary to cool the CPUs inorder to maintain safe operating conditions and assure that the CPUsfunction properly and reliably. In the past, various approaches havebeen used to cool electronic components. Typically, a heat dissipationdevice is attached to an outer surface of a CPU to remove the heattherefrom.

A typical heat dissipation device generally comprises a base forabsorbing heat from an electronic component mounted on a motherboardlocated in a computer enclosure and a plurality of fins arranged on thebase. However, as the volume of the enclosure becomes smaller andsmaller, space adjacent to the top of the base is limited and the finsare difficult to be located on the base. Generally, the fins aredisposed at another position of the enclosure far away from the base,where there is larger space for receiving the fins, and an elongate andcurved heat pipe is used to connect with the base and the fins fortransferring the heat from the base to the fins. But the elongated heatpipe is fragile and easily to be damaged by external force, whichresults in an insecure heat dissipation performance of the heatdissipation device.

Accordingly, what is needed is a heat dissipation device with a heatpipe which can be firmly and reliably protected in the enclosure and hasa steady heat dissipation performance.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a heat dissipationdevice includes a base for contacting with a heat-generating electroniccomponent, a fin assembly, a heat pipe connecting with the base and thefin assembly, and a holder connecting with the base and the fin assemblyand supporting the heat pipe. The fin assembly includes a plurality offins far apart from the base. The heat pipe includes an evaporationportion thermally engaging with the base, a condensation portionconnecting with the fin assembly and a connecting portion connectingwith the evaporation portion and the condensation portion. The holderhas a profile similar to the connecting portion of the heat pipe.

Other advantages and novel features will become more apparent from thefollowing detailed description of preferred embodiment when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present heat dissipation device can be betterunderstood with reference to the following drawings. The components inthe drawings are not necessarily drawn to scale, the emphasis insteadbeing placed upon clearly illustrating the principles of the presentheat dissipation device. Moreover, in the drawings, like referencenumerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a heat dissipation device inaccordance with a preferred embodiment of the present invention;

FIG. 2 is an exploded view of FIG. 1; and

FIG. 3 is an isometric view of a holder of the heat dissipation deviceof FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2, a heat dissipation device in accordance with apreferred embodiment of the present invention is shown. The heatdissipation device is for being mounted to a printed circuit board (notshown) to remove heat from a heat-generating electronic component (notshown) mounted on the printed circuit board, such as a CPU (not shown).The heat dissipation device comprises a base 10 for contacting the CPU,a fin assembly 20 far from the base 10, a first heat pipe 30 and asecond heat pipe 40 thermally connecting with the base 10 and the finassembly 20, and a holder 50 connecting with the base 10, the finassembly 20, the first and second heat pipes 40, 50 for supporting andstrengthening the first and second heat pipes 40, 50.

The base 10 is substantially rectangular, and is made of highly thermalconductive material such as copper or aluminum. The base 10 comprises aheat spreader 11 and a supporting portion 13 extending horizontally fromthe heat spreader 11. The heat spreader 11 has a top surface 110supporting the first and second heat pipes 30, 40 thereon and a flatbottom surface (not labeled) for directly contacting the CPU to absorbheat therefrom. The heat spreader 11 defines two parallel straightgrooves 115 at the top surface 110 thereof, for receiving the first andsecond heat pipes 30, 40 therein. The heat spreader 11 defines fourthrough holes 118 at four corners thereof. The base 10 thermally engageswith the CPU by extending four fasteners (not shown) through the throughholes 118 thereof. The four fasteners are used to extend through theprinted circuit board and threadedly engage with a back plate (notshown) on a bottom of the printed circuit board. The supporting portion13 defines a rectangular groove 130 communicated with the two grooves115 of the heat spreader 11. A depth of the groove 130 is slightlygreater than a depth of each groove 115.

The fin assembly 20 is secured far away from the base 10, consisting ofa plurality of parallel fins 23. Each of the fins 23 forms flanges (notlabeled) perpendicularly extending from a top edge and a bottom edgethereof. The fin assembly 20 defines two spaced channels 230 forreceiving the first and second heat pipes 30, 40 therein. The finassembly 20 defines a mounting hole 235 between the two channels 230. Anoutmost fin 23 of the fin assembly 20 defines two slots 237 below thetwo channels 230. The mounting hole 235 and the two slots 237 are usedfor engaging with the holder 50.

The first heat pipe 30 is flattened. The first heat pipe 30 comprises anevaporation portion 31, a condensation portion 37 and a connectingportion 35 connecting with the evaporation portion 31 and thecondensation portion 37. The evaporation portion 31 is straight andreceived in one of the grooves 115 of the base 10. The condensationportion 37 is straight and received in the one of the channels 230 ofthe fin assembly 20. The connecting portion 35 is elongated and has aserpentine configuration. In this embodiment, the connecting portion 35comprises a first curved portion 351, a second curved portion 352 and athird curved portion 353. The first curved portion 351 connects with theevaporation portion 31 and the second curved portion 353 and is at anangle to them. The third curved portion 353 connects with thecondensation portion 37 and the second curved portion 352 and is at anangle to them.

The second heat pipe 40 has a configuration similar to that of the firstheat pipe 30 and is approximately parallel to the first heat pipe 30.The second heat pipe 40 comprises an evaporation portion 41, acondensation portion 47 and a connecting portion 45 connecting with theevaporation portion 41 and the condensation portion 47. The evaporationportion 41 has a straight configuration and is received in the othergroove 115 of the base 10 and parallel to the evaporation portion 41 ofthe first heat pipe 40. The condensation portion 47 has a straightconfiguration and is received in the other channel 230 of the finassembly 20. The connecting portion 45 is elongated and has a serpentineconfiguration. The connecting portion 45 comprises a first curvedportion 451 connecting with the evaporation portion 41, a third curvedportion 453 connecting with the condensation portion 47, and a secondcurved portion 452 connecting with the first and second curved portion451, 453 and at an angle to them.

Referring to FIG. 3, the holder 50 is made of metallic material andmainly has a bottom plate 51. The bottom plate 51 is serpentine and hasa profile similar to the connecting portions 35, 45 of the first andsecond heat pipes 30, 40. The bottom plate 51 comprises an engagingportion 510 connecting with the base 10, a first extending portion 511,a second extending portion 512, and a third extending portion 513engaging with the fin assembly 20 in sequence. The first, second andthird extending portions 511, 512, 513 has a configuration correspondingto the first curved portions 351, 451, the second curved portions 352,452 and third curved portions 353, 453 of the first and second heatpipes 30, 40. Two flanges 52 extend perpendicularly from two oppositesides of the bottom plate 51 and sandwiching the connecting portion 35,45 of the first and second heat pipe 30, 40 therebetween. A height ofeach flange 52 is substantially equal to the thickness of each of thefirst and second heat pipes 30, 40 so that the flanges 52 can protectthe first and second heat pipes 30, 40. A mounting plate 53 extendsperpendicularly from a free end of the third extending portion 513 ofthe holder 50. The mounting plate 53 defines a through hole 530 thereofcorresponding to the mounting hole 235 of the fin assembly 20. Twoinserting tabs 54 are bent from the free end of the third extendingportion 513 and located at two flanks of the mounting plate 53. Eachinserting tab 54 has a tongue 540 at a top thereof for being insertedinto the slot 237 of the fin assembly 20.

In assembly, the engaging portion 510 of the holder 50 is soldered inthe rectangular groove 130 of the base 10. As such, after the engagingportion 510 is positioned in the groove 130, a top surface of theengaging portion 510 is coplanar with a bottom surface of each groove115 of the base 10. The inserting tabs 54 engage with the fin assembly20, wherein the tongues 540 of the inserting tabs 54 are inserted intothe slots 237 of the outmost fin 23. A screw 60 extends through themounting plate 53 and is engaged into the mounting hole 235 of the finassembly 20 for securely mounting the holder 50 to the fin assembly 20.The first and second heat pipes 30, 40 are soldered with the base 10 andthe fin assembly 20. Simultaneously, the first and second heat pipes 30,40 are securely mounted on the holder 50 via some mean, in thisembodiment, the first and second heat pipes 30, 40 are soldered on theholder 50.

In used, the first and second heat pipes 30, 40 connecting with the base10 and the fin assembly 20 is firmly and reliably mounted to the holder50. The elongated and serpentine connecting portions 35, 45 of the firstand second heat pipes 30, 40 are protected by the holder 50 so as toreduce a damage produced by an external force.

It is believed that the present embodiments and their advantages will beunderstood from the foregoing description, and it will be apparent thatvarious changes may be made thereto without departing from the spiritand scope of the invention or sacrificing all of its materialadvantages, the examples hereinbefore described merely being preferredor exemplary embodiments of the invention.

1. A heat dissipation device comprising: a base having a first surfaceadapted for contacting with a heat-generating electronic component and asecond surface opposite to the first surface; a fin assembly comprisinga plurality of fins far away from the base; a heat pipe comprising anevaporation portion thermally engaging with the second surface of thebase, and a condensation portion connecting with the fin assembly and anelongate connecting portion connecting with the evaporation and thecondensation portion; and a holder connecting with the base and the finassembly, the holder having a profile similar to the connecting portionof the heat pipe, the connecting portion of the heat pipe being mountedon the holder.
 2. The heat dissipation device as described in claim 1,wherein the connecting portion of the heat pipe is soldered on theholder.
 3. The heat dissipation device as described in claim 1, whereinthe holder comprises a bottom plate and two flanges extending fromopposite sides of the bottom plate.
 4. The heat dissipation device asdescribed in claim 3, wherein each of the flanges has a height similarto a thickness of the heat pipe.
 5. The heat dissipation device asdescribed in claim 1, wherein the holder forms a mounting plate from afree end thereof, a screw extending through the mounting plate andengaging with the fin assembly.
 6. The heat dissipation device asdescribed in claim 5, wherein the fin assembly defines two slots, theholder comprising two inserting tabs having two tongues inserting intothe slots of the fin assembly.
 7. The heat dissipation device asdescribed in claim 5, wherein the base defines a groove at the secondsurface, the holder having an engaging portion at the other free endreceived in the groove of the base.
 8. The heat dissipation device asdescribed in claim 1, wherein the holder is made of metallic material.9. The heat dissipation device as described in claim 1, wherein theconnecting portion of the heat pipe has a serpentine configuration, theholder having a serpentine configuration corresponding to that of theconnecting portion of the heat pipe.
 10. A heat dissipation devicecomprising: a base having a flat surface adapted for contacting with aheat-generating electronic component; a fin assembly comprising aplurality of fins far away from the base; a heat pipe comprising anevaporation portion thermally engaging with the base, and a condensationportion connecting with the fin assembly and a connecting portionconnecting with the evaporation and the condensation portion; and aholder firmly connecting with the base and the fin assembly, the holdercomprising a bottom plate and two flanges extending from opposite sidesof the bottom plate, the connecting portion of the heat pipe beingsoldered on bottom plate and sandwiched between the bottom plate. 11.The heat dissipation device as described in claim 10, wherein theprofile of the bottom plate is substantially the same as that of theconnecting portion of the heat pipe in whole.
 12. The heat dissipationdevice as described in claim 11, wherein the heat pipe is elongate andserpentine, the holder being elongate and serpentine corresponding tothe heat pipe.
 13. A heat dissipation device adapted for dissipatingheat from an electronic component, comprising: a heat spreader having aflat bottom surface adapted for contacting with the electroniccomponent; a plurality of fins remote from the heat spreader; at least aheat pipe having a first end embedded in the heat spreader at a topsurface of the heat spreader, a second end extending through the fins,and a connecting portion interconnecting the first and second ends andlocated between the first and second ends; and a strengthening retainerhaving a first portion embedded in an end of the heat spreader, and asecond portion bulked with the fins; wherein the connecting portion ofthe at least one heat pipe is received in the strengthening retainer toprevent a deformation of the at least one heat pipe.
 14. The heatdissipation device as described in claim 13, wherein the strengtheningretainer comprises a bottom plate and a pair of lateral walls extendingfrom two opposite edges of the bottom plate.
 15. The heat dissipationdevice as described in claim 14, wherein the at least one heat pipecontacts with the lateral walls of the strengthening retainer.
 16. Theheat dissipation device as described in claim 14, wherein thestrengthening retainer further comprises an engaging tab parallel to thefins, the engaging tab abutting against an outmost fin to permit a screwto extend through and engage with the outmost fin.
 17. The heatdissipation device as described in claim 16, wherein a pair of insertingtabs are formed at two flanks of the engaging tab to buckle with theoutmost fin.